Hanging walls for furnace

ABSTRACT

Wall panels are made of refractory material precast on metal frames. Hooks on the backs of the panels at their upper ends suspend the panels from rails in an exterior steel supporting frame. All of the vertical expansion of the panels from the heat of the furnace occurs in a downward direction without disturbing the roof of the furnace. The lower ends of the wall panels are free to expand and contract vertically alongside the edges of the furnace floor. All metal parts are maintained relatively cool by exposure to atmosphere on the outside of the furnace.

United States Patent Jones June 20, 1972 [54] HANGING WALLS FOR FURNACE [72] Inventor: Allen J. Jones, Fall Creek, Oreg.

[73] Assignee: Michel Lumber Company, Lake Oswego,

Oreg.

22 Filed: July 20,1970

211 Appl.No.: 56,447

[52] US. Cl ..52/285, 52/486, 52/508, 52/573, 110/1 A [51] Int. Cl E04c l/40, E04b l/94 [58] Field ofScarch ..52/484-486, 493, 52/508, 511, 410, 573, 588, 344, 294, 281, 346, 356, 361, 593, 285; 110/1 A, 1 L, 1 C

[56] References Cited UNITED STATES PATENTS 1,612,795 1/1927 Abbott ..52/484 1,657,453 1/1928 Boyd ..110/1 A 1,780,269 11/1930 Miller ....52/410 2,270,297 1/1942 Hensel.... 10/1 A 2,321,813 6/1943 l-lenzel.... ..110/1 A 2,369,100 2/1945 Youngm. ....52/486 2,389,622 l1/l945 Hensel ..52/356 2,689,987 9/1954 Berger ..52/573 2,769,410 11/1956 Over ..110/1 A 3,086,330 4/ 1963 Roudabush.. ..52/484 3,264,793 8/1966 Schlensker... .52/51 1 3,476,912 11/1969 Garrison... 52/410 FOREIGN PATENTS OR APPLICATIONS 580,594 8/1959 Canada ..llO/lA 6,548 3/1904 Great Britain ..llO/lA Primary ExaminerFrank L. Abbott Assistant Examiner-Leslie A. Braun AttarneyLee R. Schermerhorn [57] ABSTRACT Wall panels are made of refractory material precast on metal frames. Hooks on the backs of the panels at their upper ends suspend the panels from rails in an exterior steel supporting frame. All of the vertical expansion of the panels from the heat of the furnace occurs in a downward direction without disturbing the roof of the furnace. The lower ends of the wall panels are free to expand and contract vertically alongside the edges of the furnace floor. All metal parts are maintained relatively cool by exposure to atmosphere on the outside of the furnace.

2 Claims, 2 Drawing Figures PATENTEDmzo m2 INVENTOR. ALLEN J. JONES HANGING WALLS FOR FURNACE CROSS REFERENCE TO RELATED APPLICATION Reference is made to applicants copending application, Ser. No. 25,974, now U.S. Pat. No. 3,598,067 filed Apr. 6, 1970, titled DAMPER FOR HIGH TEMPERATURE OR CORROSIVE GASES, for a more comprehensive view of a typical furnace employing the present invention.

BACKGROUND OF THE INVENTION This invention relates to an improved wall construction for a furnace.

In a furnace there is considerable thermal expansion of the walls. In conventional construction the walls rest on the floor of the furnace and all vertical expansion occurs in an upward direction. The resulting expansion and contraction movements of the upper ends of the walls have particularly destructive effects on the refractory roof of the furnace, which usually rests upon or bears against the upper ends of the walls, requiring prolonged shutdowns and expensive repair from time to time.

Objects of the present invention are to provide an improved wall construction in which there is no upward expansion to damage the roof or other parts of the furnace, to provide a wall construction in which the vertical expansion occurs in a downward rather than an upward direction, to provide improved precast wall panels hung from their upper ends, and to make provision for downward expansion of the wall panels alongside the edges of the furnace floor.

SUMMARY OF INVENTION In the present construction wall panels of refractory material are precast on metal frames. The backs of the frames are equipped with hooks to hang on rails in an exterior supporting framework. Since there is no upward expansion of the panels, a roof structure resting on the upper ends of the panels is not disturbed by thennal expansion and contraction strains in the panels. The roof structure thereby has a long life without the usual necessity for shutdown and repair from time to time. The floor of the furnace terminates inside of the walls, allowing the lower ends of the wall panels to expand and contract vertically alongside the edges of the floor without producing any harmful effects.

The invention will be better understood and addiuonal objects and advantages will become apparent from the following description of the preferred embodiment illustrated on the accompanying drawing. Various changes may be made in the details of construction and arrangement of parts and certain features may be used without others. All such modifications within the scope of the appended claims are included in the invention.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a sectional view on the line 1-1 in FIG. 2, showing a furnace wall construction embodying the invention; and

FIG. 2 is a fragmentary elevation view on the line 22 in FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT The furnace has an external supporting framework comprising steel I-beam columns secured to a concrete foundation 1 1. Horizontal members 12 on top of columns 10 support roof beams 13. The roof of the furnace comprises apertured refractory blocks 15 hung on horizontal rods 16 which are suspended by vertical hanger rods 17. The upper ends of hanger rods 17 are equipped with sleeves 18 which receive horizontal bridging rods 19 resting on the lower flanges of I- beams 13.

The walls of the furnace comprise a plurality of wall panels 20. Each panel 20 has a rectangular angle iron frame 21. A sheet of expanded metal 22 spans the frame 21 with the edges of the sheet welded to the frame. Metal anchor wires 23 are welded to the mesh of sheet 22 at intervals to secure a mass of refractory material 25. Refractory material 25 is of a cementitious type which is precast on the expanded metal mesh 22 and frame 21 in a mold in horizontal position. The refractory material penetrates the openings in the mesh and thereby locks itself to the sheet 22 and becomes integral with the frame 21.

A hook 30 is welded on the outwardly projecting flange of each side member of frame 21 close to the upper end of the frame. The pair of hooks 30 on each panel 20 supports the panel on a horizontal rail 31. Rail 31 is welded to brackets 32 which are bolted to the columns 10. The load on the bolts is relieved by a supporting plate 33 welded on the column. The flanges of adjacent side members of frames 21 are secured together by bolts 34 with a strip of asbestos tape 36 interposed between the flanges in each joint.

The lower ends of frames 21 bear against a second rail comprising a horizontal pipe 35 welded to columns 10 to hold the panels 20 in vertical position substantially abutting the vertical edge surface 39 of the combustion chamber floor 40. This floor is preferably laid on a layer of insulation 41 on concrete foundation l1 and the panels 20 are of such length as to provide a space between the lower ends of the panels and concrete foundation 11 to receive a layer of compressible plastic insulating material 42.

Thus, the vertical expansion of the panels 20 is entirely in a downward direction compressing the insulating material 42. During this expansion movement the lower ends of frames 21 slide on pipe 35 and the inside face of refractory material 25 moves along the edge surface 39 of floor 40. There is no upward expansion at the upper end of the panels to disturb roof blocks 15. Horizontal expansion of the metal frames 21 is accommodated by compression of the asbestos tapes 36. The refractory blocks 25 are slightly spaced apart when cold and expand to close the gaps when hot.

The steel supporting framework 10, 13 is spaced away from the combustion chamber wall and roof and is surrounded by ambient air and effecu'vely isolated from the heat in the combustion chamber. Wall panel frames 21 are also exposed to the outside air which prevents them from attaining an excessively high temperature.

The present form of construction allows rapid and economical erection of the outer shell of the furnace and facilitates any necessary servicing and repair. When any portion of the furnace wall becomes damaged it is a relatively simple matter to remove as many of the panels 20 as may be necessary and replace them with new ones since the replacement panels are entirely prefabricated and ready to hang in place as soon as the damaged panels have been removed.

It is not necessary for a single tier of the panels 20 to extend all the way from the floor to the roof. In a high combustion chamber multiple tiers of panels may be installed one above the other, each tier hanging by books 30 on a rail 31 and bearing against a lower rail 35. In such case a space is provided between the lower edge of an upper tier and the upper edge of a lower tier and this space is filled with a layer of compressible insulating material 42. Each tier of panels expands downward, compressing the insulating material 42 without disturbing the underlying tier and without producing any upward expansion. Regardless of the number of tiers, each tier expands and contracts independently of the others.

Having now described my invention and in what manner the same may be used, what I claim as new and desire to protect by Letters Patent is:

1. In a furnace having a refractory roof subject to damage by upward expansion of the furnace walls from heat, a steel framework having columns supporting said roof, a first horizontal rail mounted on said columns and spaced inward therefrom adjacent to said roof; a plurality of wall panels, each panel comprising a peripheral angle iron frame having a sheet of expanded metal mesh welded thereto, a layer of refractory material cast on said mesh, outwardly projecting vertical side flanges on adjacent frames bolted to each other, outwardly a] under the lower ends of said panels subject to compression by said downward expansion of the panels.

2. In a furnace as defined in claim 1, a floor having a vertical edge surface confronting the inner surface of the lower end portions of said panels to accommodate vertical expansion and contraction movements of said panels relative to said floor. 

1. In a furnace having a refractory roof subject to damage by upward expansion of the furnace walls from heat, a steel framework having columns supporting said roof, a first horizontal rail mounted on said columns and spaced inward therefrom adjacent to said roof; a plurality of wall panels, each panel comprising a peripheral angle iron frame having a sheet of expanded metal mesh welded thereto, a layer of refractory material cast on said mesh, outwardly projecting vertical side flanges on adjacent frames bolted to each other, outwardly projecting hooks on said side flanges adjacent their upper ends hanging on said rail and furnishing the sole vertical support for said panels so that all of the vertical expansion of the panels is in a downward direction from said upper ends; a second horizontal rail mounted on the inside of said columns slidably engaging lower end portions of said vertical side flanges to accommodate downward expansion movement of said panels and stabilize the panels in vertical position in spaced relation to said columns; and a layer of compressible insulating material under the lower ends of said panels subject to compression by said downward expansion of the panels.
 2. In a furnace as defined in claim 1, a floor having a vertical edge surface confronting the inner surface of the lower end portions of said panels to accommodate vertical expansion and contraction movements of said panels relative to said floor. 